Ortho-hydroxyazodyestuffs and process of making same



Patented Mar. 26,

N E S ATES LEOPOLD LABKA. AND FRITZ OF QFFENBACH-ON-THE-MAIN, GERMANY, AS-

smnons TO emssnnm RATION or DELA ARE.

nswer conrormnon, onnnw YORK, N. 2., A CORPO- ORTHO-HYDROXYAZ ODYESTUFFS AND YROCESS OF MAKING SAME.

No Drawing. Application filed September 28, 1927, Serial No. 222,200,32141 in Germany October 5, 1828.

Our present invention relates to new orthohydroxyazodyestuifs corresponding probably in form of the free acids to the general formula:

wherein R means an aromatic residue, which dyestuffs may be obtained by combining aromatic ortho-hydroxydiazocompounds with 2.8-dihydroxynuphthalene-(i-carboxylic acid. (We are not sure, Whether by this process the azogroup enters in 1, 5 or -position of the naphthalene nucleus.)

The dyestuffs thus obtained are when dry blackish powders, soluble in concentrated sulfuric acid with a reddish to bluish color. They are valuable mordant dyestuffs, distinguished by an excellent evenness of their dyeings, they dye wool brownish tints turning to fast brown to black shades when after. chromed.

The 2.8 dihydroxynapthalene 6 carboxiilic acid unknown hitherto can be obtained y sulfonating the 2.6 -naphthol-carboxylic acid and subjecting the 2-naphthol-8- suli'o-6-carboxylic acid thus obtained to the caustic alkali fusion.

In order to further illustrate our invention the following examples are given, the parts being by weightand all temperatures in Centigrade degrees, but it is understood, that our invention is not limited to the particular roducts or reacting conditions mentioned t erein.

Example 1.

14, parts of et-chloro-Q-aminophenol are diazotized in the usual manner and the diazosolution thus obtained is allowed to run in E into a solution of 21 parts of 2.8-dihydroxyna hthalene-G-carboxylic acid containing; a suf iicient amount of milk of lime to neutralize all the acid. When the combination is comglete the lime is precipitated by adding caronate of soda and removed by filtration.

The dyestuif formed having probably the formula OH on HOOC - is separated by adding salt to the filtrate.

15, 4 parts of 4-nitro-2-aminophenol are diazotized in the usual manner and the (hamsolution thus obtained is allowed torun in into a solution of 21 parts of 2.8-dihydroxynaphtha]cne-(i-carboxylic acid, made alkaline by addin milk of lime. The dycstutf thus obtained loving probably the formula:

on OK is isolated as described in Example 1. It

dyes wool brown shades, turning to an oliveof an excellent fastness, when afterchromed. Example 3.

l9, 8 parts of para-nitro-ortho-amino-. salicylic acid are diazotized in the usual manner and the diazosolution thus obtained is added. to a solution of 21 parts of 2, 8-dihy- .droxynaphthaleneb-carboxylic acid, made alkaline by adding carbonate of soda. When the combination is complete the dyestufi thus obtained having probably the formula:

-COOH is salted out and worked up as usually. It dyes wool reddish brown shades. By afterchroming a brown fast to milling and potting is obtained.

' Example 1;.

Hope

is salted out and worked u in the usual manner. It dyes wool violetrown shades. B

to milling and potting.

\Vith other ortho-hydroxydiazocompounds such as of nitro-amino-para-cresol, parachloro-ortho-nitro-ortho-am inophenol, nitroaminophenolsulfonic acids or ortho-aminonaphtholsulfonic acids and with ortho-hydroxydiazoazocompounds the combination may be carried out in a corresponding manner.

We claim:

1. As new products the ortho-hydroxyazodyestuffs, corresponding probably in form of the free acids, to the general formula:

N-N-R OH (o) 3000 wherein R means an aromatic residue, which dyestuffs are when dry blackish powders,

I reddish to bluish color,

soluble in concentrated sulfuric acid with a being valuable mordant dyestuffs, dyeing wool brownish tints of an excellent evenness, turning to fast brown to black shades when afterchromed, which dyestuffs are substantially identical with those obtainable by combining aromatic ortho-hydroxydiazocompounds with 2.8-dihydroxynaphthalenc-G-carboxylie acid.

2. Process for producing new azodyestuffs which process comprises combining aromatic ortho-hydroxydiazocompounds with 2.8-dihydroxynaphthalene-Gcarboxylic acid.

3. Process for producing new azodyestulfs which process comprises combining aromatic ortho-l1ydroxydiazocompounds with 2.8-dihvdroxynaphthalene-6-carboxylic acid in an a kaline solution.

4. Fibrous material dyed with stufi's claimed in claim 1.

5. As new products the ortho-hvdroxy azodyestuffs, corresponding probably in form of the free acids to the formula:

the dyc- OH OH N -N X HOOC wherein X means hydrogen or the carboxylic y acid with a reddish to bluish color, being valafterchronnng a black-green1s obtained fast uable mordant dyestuffs dyeing wool brownish tints of an excellent evenness, turning to fast brown to olive shades, when afterchromed, which dyestuffs are substantially identical with. those obtainable by combining the diazocompounds of aromatic orthowherein X has the aforesaid signification, with 2.8-dihydroxynaphthalene-G-carboxylic acid.

In testimony whereof, we aflix our signatures.

LEOPOLD LASKA. FRITZ WEBER. 

